.\" Copyright (c) 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd February 13, 2017
.Dt ACCT 5
.Os
.Sh NAME
.Nm acct
.Nd execution accounting file
.Sh SYNOPSIS
.In sys/types.h
.In sys/acct.h
.Sh DESCRIPTION
The kernel maintains the following
.Fa acct
information structure for all
processes.
If a process terminates, and accounting is enabled,
the kernel calls the
.Xr acct 2
function call to prepare and append the record
to the accounting file.
.Bd -literal
#define AC_COMM_LEN 16

/*
 * Accounting structure version 3 (current).
 * The first byte is always zero.
 * Time units are microseconds.
 */

struct acctv3 {
	uint8_t  ac_zero;		/* zero identifies new version */
	uint8_t  ac_version;		/* record version number */
	uint16_t ac_len;		/* record length */

	char	  ac_comm[AC_COMM_LEN];	/* command name */
	float	  ac_utime;		/* user time */
	float	  ac_stime;		/* system time */
	float	  ac_etime;		/* elapsed time */
	time_t	  ac_btime;		/* starting time */
	uid_t	  ac_uid;		/* user id */
	gid_t	  ac_gid;		/* group id */
	float	  ac_mem;		/* average memory usage */
	float	  ac_io;		/* count of IO blocks */
	__dev_t   ac_tty;		/* controlling tty */

	uint16_t ac_len2;		/* record length */
	union {
		uint32_t  ac_align;	/* force v1 compatible alignment */

#define	AFORK	0x01			/* forked but not exec'ed */
/* ASU is no longer supported */
#define	ASU	0x02			/* used super-user permissions */
#define	ACOMPAT	0x04			/* used compatibility mode */
#define	ACORE	0x08			/* dumped core */
#define	AXSIG	0x10			/* killed by a signal */
#define ANVER	0x20			/* new record version */

		uint8_t  ac_flag;	/* accounting flags */
	} ac_trailer;

#define ac_flagx ac_trailer.ac_flag
};
.Ed
.Pp
If a terminated process was created by an
.Xr execve 2 ,
the name of the executed file (at most ten characters of it)
is saved in the field
.Fa ac_comm
and its status is saved by setting one of more of the following flags in
.Fa ac_flag :
.Dv AFORK ,
.Dv ACOMPAT ,
.Dv ACORE
and
.Dv ASIG .
.Dv ASU
is no longer supported.
.Dv ANVER
is always set in the above structure.
.Sh SEE ALSO
.Xr lastcomm 1 ,
.Xr acct 2 ,
.Xr execve 2 ,
.Xr sa 8
.Sh HISTORY
A
.Nm
file format appeared in
.At v7 .
The current record format was introduced on May 2007.
It is backwards compatible with the previous format,
which is still documented in
.In sys/acct.h
and supported by
.Xr lastcomm 1
and
.Xr sa 8 .
